USPTO Patents Application 10791082

WHAT IS CLAIMED IS:

1. An apparatus for reducing electromagnetic interference between a pair of
antennas attached to a wireless communications device, wherein the apparatus is

5 positioned proximate to a second antenna of the pair of antennas for intercepting
electromagnetic energy radiated from a first antenna of the pair of antennas during
transmission of a signal, and wherein the apparatus comprises a plurality of resonant
circuit elements, each being configured to resonate at or near a carrier frequency of the
transmitted signal for redirecting at least a portion of the electromagnetic energy away
10 from the second antenna, thereby reducing the electromagnetic interference at the
second antenna.

2. The apparatus of claim 1, wherein combined operation of the plurality of
resonant circuit elements enable the apparatus to operate over a relatively wide range of

15 band-gap frequencies.

3. The apparatus of claim 2, wherein the relatively wide range of band-gap
frequencies comprises the carrier frequency of the transmitted signal and extends
approximately two to four octaves above the carrier frequency.

20

4. The apparatus of claim 3, wherein the relatively wide range of band-gap
frequencies further comprises a second carrier frequency, which along with the carrier
frequency, is used by a dual-band radio module for transmitting/receiving signals via the
first antenna.

25

5. The apparatus of claim 4, wherein the relatively wide range of band-gap
frequencies further comprises a third carrier frequency, which is used by another radio
module for transmitting/receiving signals via the second antenna.

30 6. The apparatus of claim 3, wherein the carrier frequency of the transmitted signal
is equal to about 2.4 GHz, and wherein the range of band-gap frequencies extends from
about 2.3 GHz to about 9.6 GHz.

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Conley Rose, P.C

7. The apparatus of claim 1 , wherein the apparatus is configured to resonate by
setting various dimensions of the apparatus to some fraction of a wavelength of the
transmitted signal.

5 8. The apparatus of claim 7, wherein a length of the apparatus is substantially
equal to one-half of the transmission signal wavelength.

9. The apparatus of claim 8, wherein the plurality of resonant circuit elements form
a periodic surface that is substantially less than one-tenth of the transmission signal

10 wavelength.

10. The apparatus of claim 9, wherein a material composition of the apparatus is
selected from a group of conductive materials having a relative permittivity value
between about 0.0 F/m and about 1 .0 F/m and a relative permeability value between

15 about 10 H/m and about 100,000 H/m, thereby enabling the apparatus to minimize a
primarily magnetic component of the radiated electromagnetic energy.

11. The apparatus of claim 10, wherein the apparatus comprises a thin strip of
metal, which has been cut and folded into a plurality of rectangular elements, wherein

20 the plurality of rectangular elements are connected to and arranged above a common
reference plane by a plurality of vertical segments, and wherein the rectangular
elements, vertical segments and common reference plane combine to form the plurality
of resonant circuit elements.

25 12. The apparatus of claim 1 1 , wherein a lower surface of the plurality of rectangular
elements is separated from an upper surface of the common reference plane by a
dielectric material.

13. The apparatus of claim 10, wherein the apparatus comprises a thin strip of
30 metal, which has been cut and folded into a plurality of A-shaped elements separated by
a plurality of horizontal segments, and wherein the plurality of A-shaped elements and
horizontal segments combine to form the plurality of resonant circuit elements.

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Conley Rose, P.C

14. The apparatus of claim 10, wherein the apparatus comprises a thin strip of
metal, which has been cut and folded into a plurality of domed segments separated by a
plurality of slots, and wherein the plurality of domed segments and slots combine to form
the plurality of resonant circuit elements.

5

15. The apparatus of claim 10, wherein the apparatus comprises an elongated metal
structure, which has been molded to form a plurality of vertical elements, which are
periodically coupled to a common reference plane at various locations, and wherein the
plurality of vertical elements and various locations combine to form the plurality of

10 resonant circuit elements.

16. A method for reducing electromagnetic interference between two or more
antennas coupled to a wireless communication device, wherein the electromagnetic
interference occurs at a second antenna due, in part, to the close proximity of the
15 second antenna to a first antenna, and wherein the method comprises:

coupling the first antenna and the second antenna to a surface of the
communications device, wherein the first and second antennas are
spaced from each other by a relatively short distance, such that
20 electromagnetic energy radiated from the first antenna interferes with a

substantially concurrent operation of the second antenna; and

coupling an apparatus to the communication device, wherein upon intercepting
the electromagnetic energy radiated from the first antenna, the step of
25 coupling the apparatus enables a portion of the electromagnetic energy

to be redirected away from the second antenna, thereby reducing the
electromagnetic interference at the second antenna while conserving the
electromagnetic energy radiated from the first antenna.

30 17. The method of claim 16, wherein the method further comprises transmitting a
signal by radiating the electromagnetic energy from the first antenna, wherein the
electromagnetic energy propagates through free space as a plane wave having
minimum and maximum electromagnetic energy levels at various locations along the

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Conley Rose, P.C

surface of the communications device, and wherein the various locations correspond to
fractional amounts of a wavelength of the transmitted signal.

18. The method of claim 17, wherein the step of coupling the first and second
5 antennas comprises spacing the second antenna from the first antenna, such that a

receiving end of the second antenna is positioned at a furthest location of minimum
electromagnetic energy available along the surface.

19. The method of claim 18, wherein the step of coupling the apparatus comprises
10 arranging the apparatus between the first and second antennas, such that a center of

the apparatus is positioned at a location of maximum electromagnetic energy.

20. The method of claim 19, wherein the location of maximum electromagnetic
energy immediately precedes the second antenna and the furthest location of minimum

15 electromagnetic energy.

21. The method of claim 19, wherein the location of maximum electromagnetic
energy immediately follows the first antenna and a first location of minimum
electromagnetic energy.

20

22. The method of claim 19, further comprising providing the apparatus with a
periodic surface that resonates with the electromagnetic energy radiated from the first
antenna to produce a plurality of standing wave patterns, which then combine to redirect
the portion of the electromagnetic energy away from the second antenna.

25

23. The method of claim 22, wherein the steps of providing the apparatus and
coupling the apparatus enable the electromagnetic interference to be reduced without
absorbing the electromagnetic energy radiated from the first antenna or decreasing a
transmission power level of the transmitted signal.

30

24. The method of claim 23, wherein the steps of providing the apparatus and
coupling the apparatus provide an insertion loss of about -25 dB to about -35 dB
between the first and second antennas.

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